Overview
• Operator: Delta Air Lines
• Aircraft Model: Airbus A330-300
• Registration: N819NW
• Flight Number: DL-135
• Route: Amsterdam Schiphol (AMS) to Detroit Metropolitan (DTW)
• Date: 22 February 2025
• Occupants: Not specified
• Casualties: None reported
• Nature of Incident: Unusual odour on board causing flight attendants to feel unwell
Incident Summary
A Delta Air Lines Airbus A330-300, operating flight DL-135 from Amsterdam to Detroit, was cruising at FL350 approximately 320 nautical miles north-northwest of Dublin, Ireland, when the crew detected a strange odour on board. Several flight attendants began to feel unwell, prompting the crew to divert to Dublin Airport (DUB) as a precaution.
The aircraft landed safely on Dublin’s runway 28L approximately 65 minutes later and taxied to the gate. The flight crew reported that their brakes became slightly warm during taxi but otherwise experienced no additional issues.
Passengers later confirmed that an unusual smell had been present in the cabin, which affected some of the flight attendants.
The aircraft remained on the ground in Dublin for approximately 25 hours before departing for Detroit as flight DL-9935.
Sequence of Events
Pre-incident Conditions:
• Routine departure from Amsterdam Schiphol Airport (AMS) with no reported technical issues.
• The aircraft was flying transatlantic towards Detroit when the issue arose.
In-flight Occurrence:
• At FL350, approximately 320 nautical miles from Dublin, an unusual odour was detected in the cabin.
• Several flight attendants reported feeling unwell, prompting the flight crew to initiate a diversion.
• The crew coordinated with Dublin ATC for a priority landing.
Landing & Emergency Response:
• The aircraft landed safely on runway 28L at Dublin Airport approximately 65 minutes after the decision to divert.
• No emergency medical assistance was reported upon landing, but the situation was handled as a precautionary event.
• The crew noted that brakes became slightly warm during taxi but required no further intervention.
Investigation & Initial Findings
• The source of the odour remains unknown, but common factors under investigation include:
• Oil or hydraulic fluid contamination in the air conditioning system (fume event).
• Electrical or wiring issues causing an unusual smell.
• Cabin material off-gassing or onboard equipment malfunction.
• The aircraft remained grounded for approximately 25 hours before being cleared to depart as DL-9935 to Detroit.
Analysis & Safety Recommendations
• Cabin air contamination events have been reported in various Airbus models, particularly due to bleed air contamination from engine oil or hydraulic fluids.
• Airlines should conduct detailed inspections of the air conditioning and pressurization systems to ensure no contaminants enter the cabin airflow.
• Medical monitoring of affected crew members is advised, as exposure to unknown fumes can sometimes lead to short-term symptoms such as dizziness or nausea.
• Regulators may issue further guidance depending on the investigation’s findings.
Disclaimer
“This report is based on available information as of 23 February 2025. While every effort has been made to ensure accuracy, the completeness of the details cannot be guaranteed. If you are the rightful owner of any referenced materials and wish them removed, please email takedown@cockpitking.com.”
